Ceramic frit patterns currently are applied to interior and exterior glass surfaces using known silkscreen or inkjet processes. These processes typically require the entire glass system to be heated to temperatures above 500 degrees C. to fire the frit into the glass, creating a strong bond. The patterned glass optionally may be coated with a thin film coating over the ceramic frit pattern. The thus patterned and optionally coated glass may be used monolithically or built into an insulated glass (IG) unit. Typically, the surface that is patterned and optionally coated is disposed on the second surface from the sun.
FIG. 1 is a flowchart illustrating a current process for silkscreen printing a pattern on a substrate. As shown in FIG. 1, bulk glass is produced or provided in step S102. This mother substrate is then cut into appropriate sizes in step S104. The silkscreen pattern is then applied to the sized pieces in step S106, and the patterned cut pieces of glass are heat treated (e.g., heat strengthened or thermally tempered) in step S108. The high temperature process used to fire the frit is commonly conducted during the heat treating, although this is not always the case. A separate drying and/or firing process may sometimes be used; however, having separate high temperature processes for firing the frit and for heat treating the patterned substrate may be undesirable from cost perspectives (e.g., in terms of equipment costs), as well as time perspectives (e.g., as delays may be caused by multiple high-temperature heating and subsequent cooling processes). Referring once again to FIG. 1, an optional thin film coating is disposed on the heat treated pieces (e.g., via sputtering or the like) in step S110. The cut, patterned, tempered, and optionally coated pieces may be used monolithically or built into an IG unit in step S112.
The inkjet process involves a similar flow to that described above in connection with FIG. 1.
FIG. 2 is a plan view of a substrate 200 having an example frit pattern 202 formed or written thereon. As is common, the cut, patterned, tempered, and optionally coated pieces may be used in a wide variety of applications including, for example, windows in commercial settings where some light blockage is desirable, vehicle windshields (e.g., at or around the periphery of the windshield), in residential settings, etc.
The heat treatment (e.g., tempering) typically involves quenching. As will be appreciated, the heat treated products cannot be further cut or sized. Thus, in conventional process flows, as indicated above, the cutting must take place before the heat treatment. And to save on high temperature process steps, the frit typically is fired together with the heat treatment as indicated above.
Unfortunately, the current process flow suffers from several inefficiencies and further improvements are desirable. For example, silkscreen and inkjet printing processes are performed on the cut substrates, prior to heat treatment. By contrast, thin film deposition is performed after the heat treatment, e.g., to help ensure the survivability of the coating. The patterning and thin film coating of cut sheets, however, introduces inefficiencies as compared to patterning and coating the large, stock sheets of glass. Yield may be reduced, and patterning and/or coating processes may be complicated by the need to deal with multiple different sizes of cut glass substrates.
Thus, it will be appreciated that there is a need in the art for improved techniques for applying frit patterns to substrates.
Certain example embodiments of this invention relate to a method of making a coated article. A frit material is applied to a glass substrate (e.g., via a suitable wet technique). The frit material is selectively fired via a laser source (e.g., a solid state laser such as a YAG laser) so as to form or write a predetermined pattern, wherein a laser from the laser source directly or indirectly (e.g., through a or the substrate) contacts the frit material. N on-fired frit material is removed from the glass substrate (e.g., via washing). The glass substrate is cut following said removing in making the coated article. The cut coated article may be heat treated in certain example embodiments. In certain example embodiments, a thin film coating may be deposited, directly or indirectly, on the substrate prior to said cutting.
Certain example embodiments of this invention relate to a method of making an insulated glass (IG) unit is provided. A second substrate is positioned in substantially parallel, spaced apart relation to the above-described or other coated article made. A spacer is provided between the coated article and the second substrate. In certain example embodiments, where a thin film coating is provided, the coating may be located on surface 2 of the IG unit.
Certain example embodiments of this invention relate to a heat treatable coated article, comprising: a first glass substrate; a laser-fired frit material formed or written on the substrate in a predetermined pattern; and a heat treatable sputter-, PVD- or CVD-deposited coating formed over the substrate and the laser-fired frit material. The visible light transmission in regions of the coated article with the patterned frit material thereon is less than 25% post heat treatment in certain example embodiments. An IG unit incorporating the same or a similar coated article may be provided in certain example embodiments.
Certain example embodiments of this invention relate to a laser heating system. A conveyor system is provided. Laser firing means are provided for laser heating frit material applied to a glass substrate, with the laser firing means including a YAG laser source and being controllable to directly or indirectly (e.g., through a or the substrate) heat the frit material without raising the substrate temperature above 50 degrees C. At least one processor is configured to control the laser firing means so as to form or write a predetermined pattern in the frit material.
Recently, there has been a desire for silk-screen patterns and colors to enhance the appearance and solar control properties of glass fenestration systems. It oftentimes is desirable to make a pattern of a first color visible from a first side of the substrate or unit and a second color visible from a second side of the substrate or unit, with the patterns typically being the same for both sides. Some current products involve using silk screens to deposit different colors that are visible from the interior and or exterior of the substrate, e.g., with one color on top of, or aligned with, the other. In some cases, each color is applied to a different surface of a substrate or multi-pane window unit.
Unfortunately, however, the colors may become misaligned as a result of the silk-screening, printing, and/or assembly process(es), both colors may be visible from one or both sides of the assembly even when alignment is proper, etc. Indeed, dot registration is very often challenging in an analog printing process, such as silk-screening. Such analog processes typically involve application of high temperatures (typically above 500 degrees C., as described above) to fire each colored frit onto the glass. In conventional processes, each color is fired by a separate high-temperature process and, as described above, at least one high temperature process is conducted during a heat treatment (e.g., thermal tempering) process. Thus, as described above, another drawback associated with conventional two-color systems relates to the fact that the thus heat treated screen-printed sheets cannot be subsequently cut.
Thus, it will be appreciated that there is a need for improved silk screen coverage with different observable colors when viewed from the different sides (e.g., interior and exterior) of the substrate or assembly.
Certain example embodiments of this invention relate to a method of making a coated article. A first frit material is applied to a glass substrate having first and second major surfaces. The first frit material is selectively fired via a laser source so as to form or write a first predetermined pattern covering a substantial portion (e.g., at least 30%) of the first major surface of the glass substrate. A second frit material is applied over at least a portion of the first frit material and over the first major surface of the glass substrate. The second frit material is selectively fired via a or the laser source so as to form or write a second predetermined pattern covering a substantial portion of the glass substrate. Non-fired first frit material is removed from the glass substrate. Non-fired second frit material is removed from the glass substrate. After firing, the first and second frit materials cause visible characteristics (e.g., coloration) of the coated article to differ based on the major surface from which the coated article is viewed.
According to certain example embodiments, the first and second frit materials may be dried and/or allowed to dry (together or in sequence) prior to the firing of one or both of the frit materials.
According to certain example embodiments, non-fired first and second frit materials may be removed together in a single washing step, or they may be removed separately (e.g., in sequence).
In certain example embodiments, an IG or VIG unit may be made by positioning a second substrate in substantially parallel, spaced apart relation to a coated article made according to this or a similar method, and providing a spacer between the coated article and the second substrate.
Certain example embodiments relate to a heat treatable coated article. A first glass substrate is provided. A first laser-fired frit pattern is formed or written on a majority of a first major surface of the substrate. A second laser-fired frit pattern formed or written on the first laser-fired frit pattern. A heat treatable sputter-, PVD-, or CVD-deposited coating is formed over the substrate and the first and second laser-fired frit patterns. The visible transmission of the coated article with the first and second patterned frit patterns thereon is less than 25% post heat treatment. The first and second laser-fired frit patterns cause visible characteristics of the coated article to differ based on the major surface from which the coated article is viewed.
Certain example embodiments relate to a laser heating system. A conveyor is provided. Laser firing means are provided for laser heating first and second frit materials applied to a glass substrate, the laser firing means including a YAG laser source and being controllable to heat the first and second frit materials without raising the substrate temperature above 50 degrees C. At least one processor is configured to control the laser firing means so as to form or write a predetermined pattern in the first and second frit materials.
According to certain example embodiments, the laser firing means comprises first and second laser sources for selectively firing the first and second frit materials, respectively. The first and second laser sources may be in line and on a common side of the glass substrate. Alternatively, the first and second laser sources may be on opposite sides of the glass substrate, and/or the first laser source may indirectly fire the first frit material through the glass substrate and the second laser source may directly fire the second frit material.
According to certain example embodiments, the first and second frit materials are selectively fired using only one laser source. The first and second frit materials may be selectively fired at substantially the same time
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.